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Analysis of glimepiride by using derivative UV spectrophotometric method

Glimepiride (Amaryl), which is a new oral antidiabetic drug in the sulfonylurea class, was analysed by using second order derivative UV spectrophotometry. The quantification of glimepiride in dimethylformamide was performed in the wavelength range of 245-290 nm at N = 6, ?lambda = 21. The second order derivative spectra was calculated using peak to peak (lambdaDMF = 263.3-268.2 nm), peak to zero (lambdaDMF = 268.2 nm) and tangent (lambdaDMF = 263.3-271.8 nm) method for calibration curves, the linearity range of 1.00-500.00 microg ml(-1) by using the second order derivative UV spectrophotometric method. The developed method was applied to directly and easily to the analysis of the pharmaceutical tablet preparations. R.S.D. were found to be 4.18% (Amaryl tablet; 1 mg) and 2.21% (Amaryl tablet; 2 mg). The method was completely validated and proven to be rugged. The limit of quantitation and the limit of detection were found as 1.00 and 0.4 microg ml(-1), respectively. This validated derivative UV spectrophotometric method is potentially useful for a routine laboratory because of its simplicity, rapidity, sensitivity, precision and accuracy.

Polarographic behaviour of meloxicam and its determination in tablet preparations and spiked plasma.

Meloxicam is a new non-steroidal anti-inflammatory drug (NSAID), which has a higher activity cyclooxygenase-2 (COX-2) than against cyclooxygenase-1 (COX-1), with potentially high anti-inflammatory and analgesic action. The voltammetric behaviour of meloxicam was studied using direct current (DC), differential pulse polarography (DPP) and cyclic voltammetry (CV). The influence of several variables (including nature of the buffer, pH, concentration, modulation amplitude, scan rate, drop size, etc.) was examined in DPP method for meloxicam. The best DPP response was obtained in acetate buffer pH 4.88. The peak currents were measured with a static mercury drop electrode at -1.49 V versus Ag/AgCl. Calibration curve for meloxicam was linear at a concentration range from 0.38 to 15.0 microg ml(-1). The method was validated and applied to the determination of meloxicam in tablets, which were in two different dosage forms. A spectrophotometric method reported in the literature was utilized as a comparison method. There were no significant differences between the results obtained by two methods. DPP method is also available and applicable for the determination of mentioned substance in plasma. Mean recovery was 99.20+/-0.37%. It was concluded that the developed method was accurate, sensitive, precise, reproducible and useful for the quality control of meloxicam in pharmaceuticals and spiked plasma.

Determination of nimesulide in pharmaceutical dosage forms by second order derivative UV spectrophotometry

In this study, nimesulide which has been used as an analgesic, antipyretic and anti-inflammatory agent, was analyzed by using second order derivative UV spectrophotometry. The solvent, the degree of derivation, ranges of wavelength and n-value were chosen in order to optimize the conditions. The concentration of nimesulide in its solutions in ethanol and chloroform were determined between the wavelength ranges of 200 and 500 nm (n = 6, delta lambda = 21) and in the linearity ranges of 2.0-90.0 microg ml(-1) in ethanol and 2.0-50.0 microg ml(-1) in chloroform by using the values obtained from the second derivative UV spectrum of the substance. The developed second derivative UV spectrophotometric method was applied to the pharmaceutical preparations such as tablet, sachet (granule) and suspension. Tablet and sachet were analysed in ethanol while the suspension was analysed in chloroform. The results obtained from derivative UV spectrophotometry were compared with those obtained by using HPLC. It was found that the difference was not statistically important between these methods. It was concluded that developed derivative UV spectrophotometric method was accurate, sensitive, precise, reproducible and could be applied directly and easily to the pharmaceutical preparations.

HPLC method development for the simultaneous analysis of amlodipine and valsartan in combined dosage forms and in vitro dissolution studies

A simple, rapid and reproducible HPLC method was developed for the simultaneous determination of amlodipine and valsartan in their combined dosage forms, and for drug dissolution studies. A C18 column (ODS 2, 10 μm, 200 x 4.6 mm) and a mobile phase of phosphate buffer (pH 3.6 , 0.01 mol L-1):acetonitrile: methanol (46:44:10 v/v/v) mixture were used for separation and quantification. Analyses were run at a flow-rate of 1 mL min-1 and at ambient temperature. The injection volume was 20 μL and the ultraviolet detector was set at 240 nm. Under these conditions, amlodipine and valsartan were eluted at 7.1 min and 3.4 min, respectively. Total run time was shorter than 9 min. The developed method was validated according to the literature and found to be linear within the range 0.1 - 50 μg mL-1 for amlodipine, and 0.05 - 50 μg mL-1 for valsartan. The developed method was applied successfully for quality control assay of amlodipine and valsartan in their combination drug product and in vitro dissolution studies.

Electrochemical behaviour and voltammetric determination of rosuvastatin calcium in pharmaceutical preparations using a square-wave voltammetric method

In this study, the electrochemical behaviour of rosuvastatin calcium, which is a hydroxy methyl glutaryl Co-A inhibitor (a member of the statin group), used for the treatment of hypercholesterolemia and dyslipidemia was investigated using cyclic voltammetry (CV) and chronoamperometry (CA) methods. According to these studies it is assumed that the reaction is a diffusion-controlled process and irreversible. The results from the CA were calculated using Cottrells equation and the diffusion coefficient was found to be 5.79 × 10−5 ± 0.22 × 10−5 cm2 s−1. It was calculated that 2 electrons were transferred. For the determination of rosuvastatin calcium from the pharmaceutical preparations, a square wave voltammetry (SWV) method was selected and developed because it is more sensitive and faster than the other voltammetric methods. Rosuvastatin calciums reduction peak was seen at −1184 mV in pH 5 acetate buffer with a hanging mercury drop electrode (HMDE) used as the working electrode, an Ag/AgCl with saturated 3 M KCl reference electrode and a platinum wire counter electrode. 70 Hz frequency, 4 mV scan increment and 25 mV pulse amplitude were chosen as optimum parameters. This method was validated according to the ICH guidelines on analytical method validation processes. Linearity for rosuvastatin calcium was found between 0.20 and 10.00 μg mL−1. While the limit of detection for rosuvastatin calcium was 0.07 μg mL−1, the limit of quantitation was 0.20 μg mL−1. As a result of these validation studies, the selective, accurate and precise square wave voltammetric method, which gives sensitive and repeatable results, was applied to the determination of rosuvastatin calcium from pharmaceutical preparations. The results obtained from the developed method were compared with a spectrophotometric method and a capillary electrophoresis method reported in the literature and no significant difference was found statistically.

Determination of mirtazapine in tablets by UV spectrophotometric and derivative spectrophotometric methods

Mirtazapine, 1, 2, 3, 4, 10, 14b-hexahydro-2-methyl-pyrazino [2, 1-a] pyrido [2, 3-c] [G.L. Stimmel, J.A. Dopheide and S.M. Stahl, Pharmacotheraphy 17(1) (1997) 10] benzazepine, is a new and well tolerated antidepressant. It blocks pre-synaptic alpha2-adrenergic receptors and postsynaptic serotonin type 2 and type 3 receptors. The drug is rapid and completely absorbed after oral administration. Mirtazapine was analyzed by HPLC and gas chromatography with nitrogen-sensitive detection. In this study, mirtazapine was analyzed by using UV spectrophotometry, first and second order derivative spectrophotometry. The type of solvent, the degree of derivation, range of wavelength and n value were chosen in order to optimize the conditions. The concentration of mirtazapine in its methanolic solutions were determined between the wavelength range of 225-360 nm in the linearity range of 1-100, 2-100 and 1-120 microg ml(-1) by using the values obtained from UV. first-order derivative (n = 5, delta lambda = 17.5 nm) and second-order derivative (n = 9, delta lambda = 31.5 nm) spectrum of the substance, respectively. The developed UV Spectrophotometric, first-order and second-order derivative spectrophotometric methods were applied to a pharmaceutical preparation as tablet form. Developed UV and derivative UV spectrophotometric method in this study are accurate, sensitive, precise, reproducible and can be directly and easily applied to the pharmaceutical preparations.

Two derivative spectrophotometric determinations of indapamide in pharmaceutical dosage forms

Simple, fast and reliable derivative spectrophotometric methods were developed for determination of indapamide in bulk and pharmaceutical dosage forms. The solutions of standard and the sample were prepared in methanol. The quantitative determination of the drug was carried out using the first-derivative values measured at 252.8 nm (N=6) and the second-derivative values measured at 260.4 nm (N=9). Calibration graphs constructed at their wavelengths of determination were linear in the concentration range of indapamide using peak to zero 1.00-30.00 microg ml(-1) for first-derivative and 1.00-35.00 microg ml(-1) for second-derivative spectrophotometric method. The developed methods were successfully applied for the assay of pharmaceutical dosage forms which do not require any preliminary separation or treatment of the samples. The details of the statistical treatment of analytical data are also presented. The results obtained from two derivative spectrophotometry were compared with a spectrophotometric method reported in literature and no significant difference was found statistically.

Determination of Ranitidine in a Biological Material by Using Differential Pulse Adsorptive Stripping Voltammetry

Abstract A method has been developed to determine Ranitidine in stomach tissue of patients treated with this drug by using differential pulse adsorptive stripping voltammetry. A hanging mercury drop electrode was chosen as the working electrode. Extraction of ranitidine from the stomach tissue has been accomplished by using liquid-liquid extraction with chloroform. A peak at -0.56 V vs Ag/AgCl at Britten-Robinson buffer pH 2.3 has been taken for calibration curve which has been found linear in between 5.26×10−10 M to 1.27×10−5 M. Its precision was estimated by 10 successive measurernents of 2×10−7 M ranitidine The relative standard deviation was 2.8 %. The percent recovery has been found as 81 %.

Determination of Pantoprazole in Pharmaceutical Formulations and Human Plasma by Square‐Wave Voltammetry

Abstract A simple, sensitive, and selective square‐wave voltammetric method was developed for the determination of pantoprazole. The influence of the nature of the supporting electrolyte solution, pH, modulation amplitude, frequency, and scan increment was examined by square‐wave voltammetric method for pantoprazole. The best results were obtained in Britton‐Robinson buffer of pH 5.0. The peak currents were measured with hanging mercury drop electrode at −987 mV vs. Ag/AgCI. The calibration curve for pantoprazole was found as linear at a concentration range from 0.15 to 25.23 µg mL−1. The limit of detection and the limit of quantification of pantoprazole were 0.048 µg mL−1 and 0.15 µg mL−1, respectively. The validation parameters of the proposed method were evaluated. The method was applied to the pharmaceutical formulation and to both spiked plasma and the plasma of patients orally administered pantoprazole. A spectrophotometric method reported in the literature was utilized as a comparison method. There were no significant differences between the results obtained by two methods.

RP-HPLC method development and validation for estimation of rivaroxaban in pharmaceutical dosage forms

Rivaroxaban, an anti-clotting medication, acts at a crucial point in the blood-clotting process and stops the formation of blood clots. In this study, RP-HPLC method was developed for the determination of rivaroxaban in tablets (Xarelto® (10 mg)). Phenomenex Luna 5 µm C18 100 A LC Column (250 x 4.6 mm) was used at 40 oC. Isocratic elution was performed with ACN:Water (55:45 v/v) mixture. The flow rate was 1.2 mL min-1 and UV detection was at 249 nm. Internal standard (Caffeine) and rivaroxaban were eluted within 2.21 and 3.37 minutes, respectively. The developed method was validated according to the ICH guidelines and found to be linear within the range 0.005 - 40.0 µg mL-1. The method was accurate, precise, robust and rapid. Thus, it was applied successfully for the quality control assay of rivaroxaban in tablet dosage form.